Voids - Germanium

Voids - Germanium

Material Name: Germanium
Record No.: 149
Primary Chemical Element in Material: Ge
Sample Type: Wafer
Uses: Etching
Etchant Name: None
Etching Method: Dry etching
Etchant (Electrolyte) Composition: No data
Procedure (Condition): No data
Note: Figure 1 a) shows a TEM image from an array of wide Ge fins where the top 120 nm of the structures was amorphized due to the implantation. In this part of the experiment the fins are approximately 450 nm tall and 105 nm wide. Narrow fins with 20-25 nm width were completely amorphized under the same implant conditions. In the following, bright-field TEM images homogeneous gray regions are amorphous Ge and dark features are defects. The shown images are a representative selection of a larger set of images. The intrinsic Ge recrystallization rate is ~ 2 nm/s for 400 °C anneal, therefore after 3 minutes all the Ge is expected to be recrystallized. Fins are partially amorphized on the top and in the trench. Deposited carbon and platinum layers are also seen in the image. Figure 1 b) illustrates the fins after a 400 °C 3 min anneal where SPE is complete.
Reference: Maryam Shayesteh, Novel Processes, Test Structures and Characterisation for Future Germanium Technologie, PhD Thesis, NationalUniversityof Ireland, Cork, 2014, p. 117.

Figure 1: XTEM image of Ge fins, a) partially amorphized after implant. b) Although SPE is complete, defects and twin boundaries are generated.